Soil bacteria can survive lengthy periods without food or water by metabolising hydrogen. How they do this has wider implications for understanding the biology of soils, the chemistry of the atmosphere and the development of artificial catalysts to harness hydrogen as a fuel source.

Infectious diseases expert Prof Sharon Lewin explains how the HIV virus disarms our immune system and multiplies within it. She also discusses what these discoveries mean for research efforts into future treatment.

Chemistry researcher Assoc Prof Spencer Williams talks about the rapidly emerging understanding of human microbiota - the diverse and numerous microorganisms that reside on and within our bodies - and particularly how the composition of our gut flora can determine the state of our own health.

Two young science researchers discuss their investigations of microbes that threaten, respectively, human health and our food supply. We chat with Claire Gorrie about aspects of the drug-resistant bacterium Klebsiella pneumoniae, and how it's implicated in serious infections. And Rebecca Vandegeer tells us how the Barley Yellow Dwarf virus strips our wheat crops of their defences, posing a threat to food security.

Virologist and infectious diseases expert Prof John Fazakerley details the myriad threats to the global food supply from pathogen infestations in crops and livestock, and how new genetic and surveillance technologies are lending hope to keeping them in check.